Method of and means for balancing rotary bodies having radiating blades



A. L. BLAKEMORE METHOD OF AND MEANS FOR BALANCING ROTARY June 10, 1930.

BODIES HAVING RADIATING BLADES Flled June 8. 1928 W 6 wiiwww L, W l mw l HHM .7 9 A .3 m 2 We Patented June 10, 1930 UNITED STATES PATENT OFFICE ARTHUR L. BLAKE'MORE, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNOB T0 AIIEHICAN MAKGANESE STEEL COMPANY, OF CHIGAGQ ILLINOIS, A CORPORATION OF MAINE mn'rnon or AND MEANS roaiaA-LANcmo noranrnomns HAVING aamarmo BLADES Application filed June 8,

This invention relates to bodies, which, because of the high rates of speed at which they rotate in service it becomes important to have them accurately balanced about their centers ofrotation; and particularly bodies into the construction of which blade-like members enter.

It has long been proposed in the manufacture of rotary bodies, notably crank shafts for automobiles and other machinery where accurate balancing is important, to forge the blanks from which the crank axles are made with substantial masses of metal upon those portions of the crank arms or cheeks lying on the opposite side of the center of rotation from the wrists of the crank, and to place the crank when substantially completed in a testing machine adapted to. indicate imbalance relatively to the center of rotation of the entire mass that enters into the piece, the excess of metal provided-0n the opposite side of the center from the cranks being gradually removed by grinding, drilling, or other convenient'method until satisfactory balance is attained. It has also been proposed to apply to the rear surfaces of the blades of a rotor in a rotary pump, so-called coupons or fins of metal extending transvesely of the blades in lines parallel with the axis of rotation, and adapted by the removal of one or more of the coupons to bring-the center of mass into coincidence with the center of rotation.

Now, the object of the present invention is to provide an improved method of and means for balancing rotors of pumps, namely, a method and means that will avoid obstruction to radial flow of material entering between the blades, will strengthen the outer portion of the blade in a plane or planes radial to the axis of rotation as well as normal thereto, and, by reason of the range of distance from the center through which the strengthening means extends and consequent range of leverage withwhich different points in the strengthening fin will act, will permit of a very much more gradual and refined adjustment of mass than when it became necessary to remove metal from individual fins extending transversely and therefore lying 1928. serial No. 283,787.

wholly at definite distances from the center.

In the accompanying drawing- "Flgure 1 is a side elevation of a rotor of standard design in which the present inventlon' is embodied, those portions of the blades which carry the balancing fins and which are obscured by the annular Wall of the rotor, being shown in dotted lines.

F1gure 2 is a section 'on the line 2"-2 of Flgure 1; and

Figure 3 is a view similar to Figure 2 showmg a modification of the balancing fin. 1 represents a hub, 2 blades, 3 an annular Wall surrounding eye 4 of the rotor and formed integrally with the blades 2 upon one side, and 5 represents a disk or circular wall formed integrally with the blades 2 on the other side.

In order to balance the integral piece con stitutlng the rotor and identified by the numerals 1 to 5, each b1ade2 has cast integrally with its rear surface one or more fins 6 (Figures 1 and 2 where the fins terminate short of the radial extremity of the blades) or 6 (Figure 3 where the fin extends completely to the periphery), so that Within the limits of their radial dimensions they provide continuous masses of metal at gradually increaslng distance from the center of rotat1on,-from which metal can be removed by any convenient method, preferably grinding or burning torch, when as is usual the rotor is made of cast manganese steel. Not only do the fins 6 afford radially continuing surfaces from which to remove excess metal in balancing the rotor, and thereby admit of a more gradual and more refined balancing, for instance, by applying the reduction process continually along a radial surface and therefore at varying distances from the center of revolution, "according to the fineness of balance required, but said fins constitute stengthening elements for the backs of the blades and they occupy positions which do not obstruct sand, gravel, or other solids flowing in through the eye 4 and outward'between the blades of the rotor under the suctiom of the pump; or produce cupping or eddy currents that interfere with the free fiow of, material being pumped; or constitute energy absorbing element, as is the case Where coupons or transverse flanges are used. Still another advantage arising from the incorporation of radially disposed fins into the structure of blades such as 2, that are cast integrally as webs between two spaced walls such as 3 and 5, is that in the process of cooling the web-like portion of the casting can draw fluid metal from the fins and prevent the m formation of cooling cracks, metal voids, etc.

I claim:

1. A pump rotor embodying in its construction bladesiarranged around an axis of rotation, and having upon said blades, fins adapted to be'individually reduced in mass forbalancing the mass of the rotor upon its I axis of rotation; the fin upon each blade being in a plane perpendicular to the axis of rotation and of reduced dimension in the direction of the width of the blade, and leaving on the sides of the fin free and unobj structed space for the flow of material impelled by the pump. 2. A rotary pump impeller, comprising 2 blades and balancing fins on said blades; there being a plurality of such fins on a blade arranged in substantially parallel 1 planes perpendicular to the axis of rotation of the impeller, with spaces between and on 0 the outer sides of said fins for the free flow of material pumped; said fins being adapted to be reduced in mass for balancing the impeller upon its axis of rotation.

Signed at Chicago Heights, Illinois, this twenty-eighth day of May, 1928.

' ARTHUR L. BLAKEMORE. 

